One of the defendants also pleaded guilty to the charges arising from a separate cyber attack on the website of Santa Cruz County.

The defendants -- five of whom are from California -- pleaded guilty in federal court in San Jose on Thursday, admitting to carrying out a Distributed Denial of Service, or DDoS, cyber attack against PayPal three years ago.

Anonymous claimed responsibility for the attacks, which were facilitated by software tools designed to damage a computer network’s ability to function by flooding it with useless commands and information, which in turn denied service to legitimate users.

U.S. Atty. Melinda Haag of the Northern District of California announced that the following defendants pleaded guilty: